Generally, a fuel cell, which is a power generation device converting chemical energy by oxidation and reduction of hydrogen into electric energy, discharges only water (H2O) as a byproduct, does not substantially generate NOx, SOx, and dust, generates a low amount of CO2, and does not substantially generate noise unlike existing other chemical energy. Therefore, the fuel cell has been prominent as the next-generation alternative energy.
The fuel cell includes unit cells basically including an electrolyte plate containing an electrolyte, an anode, a cathode, a separator separating the electrolyte plate containing the electrolyte, the anode, and the cathode from one another, and the like. However, since the unit cell generally generates a low voltage of 0.6 to 0.8V, a fuel cell stack 1 in which several tens or several hundreds of unit cells 30 are stacked is configured to obtain a desired electric output, as illustrated in FIG. 1. In addition, a membrane-electrode assembly (MEA) is configured by forming the electrolyte plate containing the electrolyte, the anode, and the cathode integrally with one another, and patterns are formed in the separator separating the electrolyte plate containing the electrolyte, the anode, and the cathode from one another to allow a fuel and air to flow.
In addition, various fuels such as natural gas, petroleum, coal gas, methanol, and the like, may be used in the fuel cell, and are converted into hydrogen through a fuel reforming device and are used.
However, in the fuel cell configured in a form of the fuel cell stack as described above, water generated by a bond between oxygen and hydrogen in unit cells (end cells) positioned at the outermost portions in a stack direction of the unit cells remains, and is frozen in the end cells due to a cold external temperature during winter. Therefore, electricity is not generated in the end cells, such that initial start ability and oscillation ability of the fuel cell are deteriorated.